1. Field of the Disclosure
The present disclosure relates to an endoscope device introduced into a living body to obtain an in-vivo image.
2. Description of the Related Art
Technology of detecting a motion amount between frames based on a current frame and a previous frame corresponding to image signals temporally adjacent to each other generated by an imaging device to reduce a noise component of the current frame according to the motion amount is conventionally known as noise reduction processing (hereinafter, referred to as “NR processing)) of reducing the noise component included in the image signal generated by the imaging device such as a CCD (charge coupled device) and a CMOS (complementary metal oxide semiconductor) (see Japanese Patent Application Laid-open No. 2005-150903).
Technology of detecting the motion amount between the frames based on a pixel value of a pixel which receives light transmitted through a filter which transmits a specific color component out of the image signal generated by the imaging device to reduce the noise component of the current frame according to the motion amount is known as another NR processing (see Japanese Patent Application Laid-open No. 2011-029722).
Recently, the endoscope device uses a narrow band imaging (NBI) system in which illumination light formed of two types of narrow band light included in blue and green light wavelength bands (hereinafter, referred to as “narrow band illumination light”) is used for observing a capillary, a mucosal fine pattern and the like on a mucous membrane surface of the living body in addition to white light imaging (WLI) system in which white illumination light (hereinafter referred to as “white illumination light”) is used.
However, when the above-described white illumination light imaging system and narrow band imaging system are performed, when the NR processing is performed based on the pixel value output from the pixel on which a specific filter is provided, the pixel value of each pixel differs depending on different characteristics of the imaging system, so that there is a problem that the noise component may be appropriately reduced in one imaging system but the noise component may not be appropriately reduced in the other imaging system.
There is a need for an endoscope device capable of appropriately reducing the noise component in both the white illumination light imaging system and the narrow band imaging system.